Despite advances in metallurgy in the past decade, there is still not a facile technique for producing nonporous, high-strength metal alloys at low temperatures. A widely used method consists of mixing two metals with different melting temperatures and raising the temperature to just above that of the lowest melting metal. This method has the advantage of forming alloys at relatively low temperatures and, moreover, enables them to be shaped into a desirable configuration at low temperatures and low pressures. The method is particularly advantageous in instances where a reactive metal with a high melting temperature is sought to be alloyed to a relatively low-melting and less reactive metal. Nevertheless, however, the alloys produced by this technique are not strong enough for a wide number of applications calling for high-strength alloys.
Other methods for producing metal alloys also generally do not readily yield nonporous high-strength products at low temperatures. For instance, the processes described in U.S. Pat. No. 2,581,252, No. 2,714,556, and No. 4,432,935 all yield porous metal alloys. Several other methods involve an impregnation process that comprises introducing into a porous structure one or more metals and heating the object to form a structural alloy. A representative example of this process is U.S. Pat. No. 4,155,755.
It is apparent that it is desirable to have a process for producing nonporous metal alloys of high strength that can be generated at low temperatures.